From 24bb95886aeefcc7ae456a2a9bed819ed8d2739f Mon Sep 17 00:00:00 2001
From: Russ Allbery <rra@debian.org>
Date: Sat, 3 Jul 2010 22:25:04 -0700
Subject: [PATCH] Architecture restrictions are supported for binary packages

Document architecture restrictions for binary relationship fields
as well as build relationships, with their limitation that they're
only valid in source package control files and are used to generate
the fields in the binary package.
---
 policy.sgml | 64 +++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 45 insertions(+), 19 deletions(-)

diff --git a/policy.sgml b/policy.sgml
index bad28af..316f753 100644
--- a/policy.sgml
+++ b/policy.sgml
@@ -4373,21 +4373,24 @@ Depends: libc6 (>= 2.2.1), exim | mail-transport-agent
 	</p>
 
         <p>
-          All fields that specify build-time relationships
+	  Relationships may be restricted to a certain set of
+	  architectures.  This is indicated in brackets after each
+	  individual package name and the optional version specification.
+	  The brackets enclose a list of Debian architecture names
+	  separated by whitespace.  Exclamation marks may be prepended to
+	  each of the names.  (It is not permitted for some names to be
+	  prepended with exclamation marks while others aren't.)
+	</p>
+
+	<p>
+	  For build relationship fields
 	  (<tt>Build-Depends</tt>, <tt>Build-Depends-Indep</tt>,
-	  <tt>Build-Conflicts</tt> and <tt>Build-Conflicts-Indep</tt>)
-	  may be restricted to a certain set of architectures.  This
-	  is indicated in brackets after each individual package name and
-	  the optional version specification.  The brackets enclose a
-	  list of Debian architecture names separated by whitespace.
-	  Exclamation marks may be prepended to each of the names.
-	  (It is not permitted for some names to be prepended with
-	  exclamation marks while others aren't.) If the current Debian
-	  host architecture is not in this list and there are no
-	  exclamation marks in the list, or it is in the list with a
-	  prepended exclamation mark, the package name and the
-	  associated version specification are ignored completely for
-	  the purposes of defining the relationships.
+	  <tt>Build-Conflicts</tt> and <tt>Build-Conflicts-Indep</tt>), if
+	  the current Debian host architecture is not in this list and
+	  there are no exclamation marks in the list, or it is in the list
+	  with a prepended exclamation mark, the package name and the
+	  associated version specification are ignored completely for the
+	  purposes of defining the relationships.
 	</p>
 
 	<p>
@@ -4403,6 +4406,29 @@ Build-Depends: kernel-headers-2.2.10 [!hurd-i386],
 	  <tt>gnumach-dev</tt> only on hurd-i386.
 	</p>
 
+	<p>
+	  For binary relationship fields, the architecture restriction
+	  syntax is only supported in the source package control
+	  file <file>debian/control</file>.  When the corresponding binary
+	  package control file is generated, the relationship will either
+	  be omitted or included without the architecture restriction
+	  based on the architecture of the binary package.  This means
+	  that architecture restrictions must not be used in binary
+	  relationship fields for architecture-independent packages
+	  (<tt>Architecture: all</tt>).
+	</p>
+
+	<p>
+	  For example:
+	  <example compact="compact">
+Depends: foo [i386], bar [amd64]
+	  </example>
+	  becomes <tt>Depends: foo</tt> when the package is built on
+	  the <tt>i386</tt> architecture, <tt>Depends: bar</tt> when the
+	  package is built on the <tt>amd64</tt> architecture, and omitted
+	  entirely in binary packages built on all other architectures.
+	</p>
+
 	<p>
 	  If the architecture-restricted dependency is part of a set of
 	  alternatives using <tt>|</tt>, that alternative is ignored
@@ -4417,11 +4443,11 @@ Build-Depends: foo [!i386] | bar [!amd64]
 	</p>
 
         <p>
-	  All fields that specify build-time relationships may also be
-	  restricted to a certain set of architectures using architecture
-	  wildcards.  The syntax for declaring such restrictions is the
-	  same as declaring restrictions using a certain set of
-	  architectures without architecture wildcards.  For example:
+	  Relationships may also be restricted to a certain set of
+	  architectures using architecture wildcards.  The syntax for
+	  declaring such restrictions is the same as declaring
+	  restrictions using a certain set of architectures without
+	  architecture wildcards.  For example:
           <example compact="compact">
 Build-Depends: foo [linux-any], bar [any-i386], baz [!linux-any]
           </example>
-- 
2.39.5